Patellofemoral Joint Disorders

and Treatment Options

Gregory Purnell, MD

Allegheny Health Network

Department of Orthpoaedic Surgery

Orthopaedic Update 2015

Nemacolin Woodlands Conference Center

Farmington, PA

March 20-22, 2015

DISCLOSURES

I do not have anything to disclose

Overview

Anatomy and Basic

Biomechanics

Classification of

Patellofemoral Disorders

Treatment Options

Patellofemoral Basics and

Anatomy

Thickest articular cartilage in the body

Up to 5-7mm at central ridge

Joint reaction forces

0.5 x BW walking/biking

3.3 x BW ascend stairs

5 x BW descend stairs

7.8 x BW squatting

20 x BW deep squatting

Contact Areas

Huberti JBJS 1984

Facet orientation

Wiberg classification

I 24%

II 57%

III 19%

IV 1%

Believed to be determined

by loading during

development

Wiberg 1941 and Baumgarti 1944

Soft Tissue Stabilizers

Active and Passive

Medial Medial Retinaculum and

MPFL MPFL runs from upper medial 2/3’s of

patella to adductor tubercle

Vastus Medialis obliquus Pulls at angle 55 to 70 degrees

contribution at 30 deg

Medial Patellofemoral

Ligament

Main constraint in

EARLY flexion

Checkrein to lateral

translation

Taut and elongated in

full extension

Decreasing contribution

after 30 degrees

Shortens and lax with

increasing flexion

MPFL on MRI

Lateral Stabilizers

Lateral retinaculum Superficial oblique fibers

attach to ITB

Deep transverse fibers

connect to ITB, tibia, & lateral

epicondyle

IT band moves posteriorly

in flexion which contributes

to tilt and subluxation

Vastus lateralis Tight with obligatory

dislocators

Bony stabilizers

Geometry of the patella

and trochlea

Lateral trochlea primary

passive restraint to

lateral translation

Important with increasing

flexion angles when

MPFL becomes lax

HISTORY and PHYSICAL

History

Typically anterior knee

pain

May be confused with

meniscal pathology

Explore any trauma

History

Overuse Injuries

Inciting activities

Squats, stairs,

skiing, biking uphill

Movie theater sign

History

Instability Episode of frank subluxation

or dislocation

Objective vs. subjective

instability

Mechanical symptoms Grinding

Catching

Physical Exam

Observation, including gait

Standing alignment

Hip excess anteversion

Tibial Torsion

Foot position

Physical Exam

Palpation Tends to be anterior to

course of MCL

Medial synovial plica???

ROM and strength testing

Flexibility hamstrings/quads/ITB

Physical Exam

Patellar mobility

Assess quadrants

Special maneuvers Apprehension

Compression/Grind

Tift lateral tilt

Lateral translation/J sign

Complete ligament exam

J Sign

Lateral translation with

extension

Moves medial with

flexion

Lateral instability

Q-angle

Angle of pull of the

quadriceps

Men 15

Women 18

Inadequate measure

of tubercle

malalignment Post et al 2002

Limb Alignment

Miserable Malalignment

Femoral anteversion Increases in anteversion

rotates knee internally relative to pull of quads

External tibial torsion Tubercle moved laterally

increasing angle

Valgus knee alignment Physiologic or Pathologic

Hyper-pronation

Patellofemoral Malalignment

Multifactorial

May present with pain or mechanical issues

Overall limb alignment

Trochlear geometry

Patellar tilt

Quadriceps function

J-sign

IMAGING

Radiologic evaluation

Plain X-rays AP, Lateral, Axial view

Radiographic measurements Sulcus angle

Tilt angle

Congruence angle

CT scan Very good axial imaging

Shows osseous changes

Tracking CT – varying degrees of flexion

MRI Articular cartilage

Ligament injuries

Merchant View

Sulcus Angle

Normal 137 degrees

Elevated in trochlear

hyposplasia

Aglietti et all 1983

Lateral Tilt Angle

Angle should open

laterally

Parallel or medial

increases chance

subluxation

Patellar tilt

Congruence Angle

Normal -6 to -10

degrees

Patella apex should be

medial to bisected

trochlea

Trochlear Dysplasia

Dejour et al. Knee Surg Sports Traumatol Arthrosc 1994

Cross over

sign Trochlear

prominence

Trochlear Hypoplasia

TT-TG Distance

Measures lateralization

of tibial tubercle Dejour 1994

Normal 10-12 mm

Instability >15 mm Schoettle et al 2006

>20 mm necessary for

distal realignment International Patellofemoral Study

Group 2006

MRI Calculation of TT-TG

Initial calculations on CT

scan Dejour et al. 1994

Excellent inter-rater

reliability both CT and MR Camp et al AJSM 2013

Pediatric TT-TG distance

10-12 mm adults

May be less in

pediatric pts

Plotted on

growth curve

Dickens et al. JBJS 2014

Check for Patella Alta

Insall-Salvati

Blackburne-Peel

Treatment Options?????

Conservative Treatment

Rest, Ice, NSAIDs

Rarely involve significant inflammation

Physical Therapy

Mainstain of treatment – several months

Patella Tracking Braces

McConnell Taping

Orthoses for hyperpronation or

pes planus

Therapeutic Exercises

Maintain Motion !!!

Quadriceps, Lateral retinacular, ITB

stretching

Quadriceps strengthening – VMO

Painfree arc

Terminal extension to maximize quad

demand

I prefer resistance exercises no greater

than 45 degrees flexion

Avoid Isokinetic – increases articular

pressure

Remember contact stresses !!!

Surgical Treatment

Spectrum of pathology

First identify the pathoanatomy

(Fulkerson and Post)

Patellofemoral pain with malalignment

Patellofemoral pain without malalignment

Patellofemoral instability +/- malalignment

Soft-tissue disorders without

malalignment

Patella dislocations

Lateral patella tilt

Articular degeneration with/without

malalignment

Surgical Treatment

Arthroscopic or Open Lateral

Release

Distal Realignment

Tibial tubercle transfer

AMZ, distalization

Proximal Realignment

Soft tissue reconstruction

Cartilage Restoration

Arthroplasty

Combined procedures

Lateral Patellar Tilt

Lateral patellar pain with tight

retinaculum and tilt

Inability to elevate above horizon

Release only if minimal

degenerative changes

Lateral Retinacular

Release

Only indication is lateral tilt

Arthroscopic (can be done open in

conjunction with other procedures)

Ablation device with coagulation

function

Patella must evert above horizontal

Iatrogenic Medial Instability Hughston et al AJSM 1988

Check alignment & tracking pre/post

release LRR alone will not correct tracking or

alignment

Distal Realignment

Can be used to correct actual

anatomic alignment

TT-TG > 20 mm

Corrects lateralization of tubercle

Variety of osteotomies have

been described

Medial, anterior, distal, combo

Consider condition and desired

direction of transfer

Avoid posterior transfers

Distal Realignment

Hauser Procedure (1938)

Medial tibial tubercle transfer

Resultant posterior displacement of tubercle

Increased rates of DJD

Roux-Elmslie-Trillat

Medial transfer w/o posterior displacement

Included medial tightening & lateral release

Much better than Hauser

Avoid if significant degenerative changes

Distal realignment

Maquet Transfer

Not actually for malalignment

Pure anterior transfer

Need large bone graft

Used for degenerative changes

Decreases joint reaction force

Soft tissue complications

Mainly with very large elevations

Probably OK if 1-1.5 cm elevation

Distal Realignment

Fulkerson Osteotomy (AMZ) Anteromedial transfer

Combination of chondral changes and malalignment

Oblique cut

Large surface area for healing

Ideal for distal and lateral patella lesions

Less successful for proximal and medial changes

Fulkerson CORR 1983

Fulkerson

Fulkerson Am J Sports

Med 1997

Fulkerson Post-Op Rehab

Protected weight-bearing

I prefer WBAT with brace

Reports of delayed stress fracture

with early weight-bearing

Brace locked initially

Open based on quad control

Early ROM and patella

mobilization

Maintain lateral flexibility

Return to sports 6 months

Radiographic evidence of union

Dynamic Instability without

Static Malalignment

Usually indicative of soft tissue injury

History of dislocation

Conservative treatment first

Don’t forget to treat hyper-pronation

Examine arthroscopically

Proximal realignment procedure

Torn

MPFL

Proximal Realignment

May combine with

previous mentioned

procedures

Lateral release only

indicated –avoid if

hypoplastic trochlea

Distal realignment only if

combined problem

Proximal Realignment

Historically

Insall: Made medial arthrotomy, advanced

medial soft tissues over anterior patella and

sutured to lateral border

Today

Mainly arthroscopic or mini-open plication

MPFL reconstruction

Proximal Realignment

For all procedures

Avoid pulling patella

medially

MPFL should act as

check-reign to prevent

subluxation

If medial pull is

necessary then do

distal realignment

Soft Tissue Advancement

Need residual MPFL function

Mini-open

Several cm incision over

superomedial corner of patella

Check integrity of MPFL

Advance VMO and MPFL as

needed to patella

Arthroscopic Technique

Imbrication of medial tissue

Difficult to examine MPFL

integrity

Tension harder to assess

Arthroscopic Imbrication

Medial Patellofemoral

Ligament Reconstruction

Medial structures not

amenable to tightening or

hypoplastic trochlea

I prefer gracilis allograft

Avoid proximal femoral

insertion

Set proper tension to

avoid increasing medial

contact stresses

Re-create anatomic MPFL, not isometry

Favorable anisometry (Thaunat et al. Knee 2007)

Schöttle et. Am J Sports Med 2007

Post OP MPFL Rehab

0-2 weeks TDWB

Brace locked for weight-bearing

Quad sets/heel slides/SLR in full extension

2-6 weeks WBAT progression

Brace to 90 degrees

ROM 90+ flexion by 6 weeks

6-12 weeks Full painless ROM

Progress quad strengthening

3+ months Functional, agility and advanced strengthening

Return to sports 3-4 months

Treatment option for

Trochlear Dysplasia

Dysplasia with normal TT-TG

MPFL reconstruction Steiner AJSM 2006

Dysplasia elevated TT-TG

MPFL reconstruction + bony

procedure Fulkerson JAAOS 2011

Trochleoplasty as last option Severe dysplasia refractory to other options

Hypoplastic Trochlea

MPFL reconstruction

Patella Alta

Consider

distalization

Patellofemoral Chondral

Lesions

Medial Facet - Dislocations

Lateral Facet -

Conservative Options

Avoid aggressive PT

Stop offending activities

Stay within comfort range

MRI to Assess Articular

Cartilage

Patellofemoral lesions

Arthroscopy

debridement/chondroplasty

Anterior Displacing Osteotomies

Fulkerson

Steeper angle for less medialization

Maquet

avoid huge grafts

Patellofemoral Chondral Lesions

Unpredictable results for larger lesions Noyes et al. Arthroscopy 2013

Microfracture/Chondral grafts/ACI

Less successful than condylar lesions

Osteochondral autologous transfers

do not reproduce cartilage thickness

ACI and other grafts survivorship

decrease with time Nawaz et al JBJS 2014

Probably need osteochondral allograft

for larger lesions in younger

patients???

Articular Degeneration

Patella chondral changes

correlate poorly with pain

Thickness of cartilage ???

Underlying bony changes

are better indicator

Edema, cystic changes

Assess location of chondral

damage

Check alignment carefully

Patellofemoral Arthrosis

Post-Traumatic OA

Surgery for PFJ OA

Patellectomy

Decreases pain

Quad function impaired Variable but up to 50% loss

Mainly of historical interest

Patellofemoral arthroplasty Older, lower demand patients

Not as well proven as TKA

Correct alignment

TKA

Gold standard if coexistent medial/lateral arthrosis

Patellofemoral Procedures

Post Operative Rehabilitation

Specific to the underlying problem and

the surgical treatment

Emphasis on achieving motion

Limited with cartilage procedure

Typically protected weight-bearing

Return to sports 3-12 + months

MPFL reconstruction – 3 months

Fulkerson osteotomy – 6 months

Cartilage Restoration - 12+ months

Summary

Wide spectrum of problems

Identify the pathology

Conservative treatment mainstay

Surgery specific to pathoanatomy

Questions???

Case 1

14 y.o female

High school basketball

Bilateral anterior knee pain

R>L

No improvement with 3 months PT

Lateral Release

Arthroscopic Medial Imbrication

3 Months Post-op

Full motion Right knee

No pain

Same surgical procedure for Left knee

Case 2

21 y.o old male

Second time dislocation jumping off back

of pick up truck

First dislocation as teenager

Required manual reduction in ED

Works on family farm

ISSUES and OPTIONS???

2nd dislocation

Shallow trochlea

Torn MPFL

Lateralized tibial tubercle

SURGERY

Proximal Realignment

MPFL reconstruction

Distal Realignment

AMZ transfer

Case 3

24 y.o male history of multiple lateral

dislocations

Previous soft tissue procedures in past

as teenager

8 weeks PT with no improvement

Persistent lateral instability

Requiring brace/crutches for ambulation

Combined Problem

TT-TG

12mm

SURGERY

Proximal Realignment

– MPFL reconstruction

Cartilage Restoration

– Juvenile Particulate

Cartilage Cell

Implantation

Medial Facet

Defect

THANK YOU